033539e268
PR binutils/17512 * format.c (bfd_check_format_matches): Check for a matching vector before using match priorities. * mach-o.c (bfd_mach_o_canonicalize_one_reloc): Fix off-by-one errors with previous delta.
560 lines
16 KiB
C
560 lines
16 KiB
C
/* Generic BFD support for file formats.
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Copyright (C) 1990-2014 Free Software Foundation, Inc.
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Written by Cygnus Support.
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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MA 02110-1301, USA. */
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/*
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SECTION
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File formats
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A format is a BFD concept of high level file contents type. The
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formats supported by BFD are:
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o <<bfd_object>>
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The BFD may contain data, symbols, relocations and debug info.
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o <<bfd_archive>>
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The BFD contains other BFDs and an optional index.
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o <<bfd_core>>
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The BFD contains the result of an executable core dump.
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SUBSECTION
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File format functions
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*/
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#include "sysdep.h"
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#include "bfd.h"
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#include "libbfd.h"
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/* IMPORT from targets.c. */
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extern const size_t _bfd_target_vector_entries;
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/*
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FUNCTION
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bfd_check_format
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SYNOPSIS
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bfd_boolean bfd_check_format (bfd *abfd, bfd_format format);
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DESCRIPTION
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Verify if the file attached to the BFD @var{abfd} is compatible
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with the format @var{format} (i.e., one of <<bfd_object>>,
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<<bfd_archive>> or <<bfd_core>>).
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If the BFD has been set to a specific target before the
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call, only the named target and format combination is
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checked. If the target has not been set, or has been set to
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<<default>>, then all the known target backends is
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interrogated to determine a match. If the default target
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matches, it is used. If not, exactly one target must recognize
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the file, or an error results.
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The function returns <<TRUE>> on success, otherwise <<FALSE>>
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with one of the following error codes:
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o <<bfd_error_invalid_operation>> -
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if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or
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<<bfd_core>>.
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o <<bfd_error_system_call>> -
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if an error occured during a read - even some file mismatches
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can cause bfd_error_system_calls.
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o <<file_not_recognised>> -
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none of the backends recognised the file format.
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o <<bfd_error_file_ambiguously_recognized>> -
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more than one backend recognised the file format.
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*/
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bfd_boolean
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bfd_check_format (bfd *abfd, bfd_format format)
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{
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return bfd_check_format_matches (abfd, format, NULL);
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}
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struct bfd_preserve
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{
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void *marker;
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void *tdata;
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flagword flags;
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const struct bfd_arch_info *arch_info;
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struct bfd_section *sections;
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struct bfd_section *section_last;
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unsigned int section_count;
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struct bfd_hash_table section_htab;
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};
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/* When testing an object for compatibility with a particular target
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back-end, the back-end object_p function needs to set up certain
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fields in the bfd on successfully recognizing the object. This
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typically happens in a piecemeal fashion, with failures possible at
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many points. On failure, the bfd is supposed to be restored to its
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initial state, which is virtually impossible. However, restoring a
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subset of the bfd state works in practice. This function stores
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the subset. */
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static bfd_boolean
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bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve)
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{
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preserve->tdata = abfd->tdata.any;
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preserve->arch_info = abfd->arch_info;
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preserve->flags = abfd->flags;
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preserve->sections = abfd->sections;
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preserve->section_last = abfd->section_last;
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preserve->section_count = abfd->section_count;
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preserve->section_htab = abfd->section_htab;
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preserve->marker = bfd_alloc (abfd, 1);
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if (preserve->marker == NULL)
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return FALSE;
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return bfd_hash_table_init (&abfd->section_htab, bfd_section_hash_newfunc,
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sizeof (struct section_hash_entry));
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}
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/* Clear out a subset of BFD state. */
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static void
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bfd_reinit (bfd *abfd)
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{
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abfd->tdata.any = NULL;
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abfd->arch_info = &bfd_default_arch_struct;
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abfd->flags &= BFD_FLAGS_SAVED;
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bfd_section_list_clear (abfd);
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}
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/* Restores bfd state saved by bfd_preserve_save. */
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static void
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bfd_preserve_restore (bfd *abfd, struct bfd_preserve *preserve)
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{
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bfd_hash_table_free (&abfd->section_htab);
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abfd->tdata.any = preserve->tdata;
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abfd->arch_info = preserve->arch_info;
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abfd->flags = preserve->flags;
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abfd->section_htab = preserve->section_htab;
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abfd->sections = preserve->sections;
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abfd->section_last = preserve->section_last;
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abfd->section_count = preserve->section_count;
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/* bfd_release frees all memory more recently bfd_alloc'd than
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its arg, as well as its arg. */
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bfd_release (abfd, preserve->marker);
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preserve->marker = NULL;
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}
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/* Called when the bfd state saved by bfd_preserve_save is no longer
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needed. */
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static void
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bfd_preserve_finish (bfd *abfd ATTRIBUTE_UNUSED, struct bfd_preserve *preserve)
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{
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/* It would be nice to be able to free more memory here, eg. old
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tdata, but that's not possible since these blocks are sitting
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inside bfd_alloc'd memory. The section hash is on a separate
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objalloc. */
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bfd_hash_table_free (&preserve->section_htab);
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preserve->marker = NULL;
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}
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/*
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FUNCTION
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bfd_check_format_matches
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SYNOPSIS
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bfd_boolean bfd_check_format_matches
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(bfd *abfd, bfd_format format, char ***matching);
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DESCRIPTION
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Like <<bfd_check_format>>, except when it returns FALSE with
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<<bfd_errno>> set to <<bfd_error_file_ambiguously_recognized>>. In that
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case, if @var{matching} is not NULL, it will be filled in with
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a NULL-terminated list of the names of the formats that matched,
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allocated with <<malloc>>.
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Then the user may choose a format and try again.
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When done with the list that @var{matching} points to, the caller
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should free it.
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*/
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bfd_boolean
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bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
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{
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extern const bfd_target binary_vec;
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const bfd_target * const *target;
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const bfd_target **matching_vector = NULL;
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const bfd_target *save_targ, *right_targ, *ar_right_targ, *match_targ;
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int match_count, best_count, best_match;
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int ar_match_index;
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struct bfd_preserve preserve;
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if (matching != NULL)
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*matching = NULL;
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if (!bfd_read_p (abfd)
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|| (unsigned int) abfd->format >= (unsigned int) bfd_type_end)
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{
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bfd_set_error (bfd_error_invalid_operation);
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return FALSE;
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}
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if (abfd->format != bfd_unknown)
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return abfd->format == format;
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if (matching != NULL || *bfd_associated_vector != NULL)
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{
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bfd_size_type amt;
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amt = sizeof (*matching_vector) * 2 * _bfd_target_vector_entries;
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matching_vector = (const bfd_target **) bfd_malloc (amt);
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if (!matching_vector)
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return FALSE;
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}
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/* Presume the answer is yes. */
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abfd->format = format;
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save_targ = abfd->xvec;
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preserve.marker = NULL;
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/* If the target type was explicitly specified, just check that target. */
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if (!abfd->target_defaulted)
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{
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if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) /* rewind! */
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goto err_ret;
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right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
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if (right_targ)
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goto ok_ret;
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/* For a long time the code has dropped through to check all
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targets if the specified target was wrong. I don't know why,
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and I'm reluctant to change it. However, in the case of an
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archive, it can cause problems. If the specified target does
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not permit archives (e.g., the binary target), then we should
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not allow some other target to recognize it as an archive, but
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should instead allow the specified target to recognize it as an
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object. When I first made this change, it broke the PE target,
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because the specified pei-i386 target did not recognize the
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actual pe-i386 archive. Since there may be other problems of
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this sort, I changed this test to check only for the binary
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target. */
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if (format == bfd_archive && save_targ == &binary_vec)
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goto err_unrecog;
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}
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/* Since the target type was defaulted, check them all in the hope
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that one will be uniquely recognized. */
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right_targ = NULL;
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ar_right_targ = NULL;
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match_targ = NULL;
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best_match = 256;
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best_count = 0;
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match_count = 0;
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ar_match_index = _bfd_target_vector_entries;
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for (target = bfd_target_vector; *target != NULL; target++)
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{
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const bfd_target *temp;
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/* Don't check the default target twice. */
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if (*target == &binary_vec
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|| (!abfd->target_defaulted && *target == save_targ)
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|| (*target)->match_priority > best_match)
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continue;
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/* If we already tried a match, the bfd is modified and may
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have sections attached, which will confuse the next
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_bfd_check_format call. */
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bfd_reinit (abfd);
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/* Change BFD's target temporarily. */
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abfd->xvec = *target;
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if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
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goto err_ret;
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/* If _bfd_check_format neglects to set bfd_error, assume
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bfd_error_wrong_format. We didn't used to even pay any
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attention to bfd_error, so I suspect that some
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_bfd_check_format might have this problem. */
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bfd_set_error (bfd_error_wrong_format);
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temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
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if (temp)
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{
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match_targ = temp;
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if (preserve.marker != NULL)
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bfd_preserve_finish (abfd, &preserve);
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if (abfd->format != bfd_archive
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|| (bfd_has_map (abfd)
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&& bfd_get_error () != bfd_error_wrong_object_format))
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{
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/* This format checks out as ok! */
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right_targ = temp;
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/* If this is the default target, accept it, even if
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other targets might match. People who want those
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other targets have to set the GNUTARGET variable. */
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if (temp == bfd_default_vector[0])
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goto ok_ret;
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if (matching_vector)
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matching_vector[match_count] = temp;
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match_count++;
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if (temp->match_priority < best_match)
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{
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best_match = temp->match_priority;
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best_count = 0;
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}
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best_count++;
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}
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else
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{
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/* An archive with no armap or objects of the wrong
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type. We want this target to match if we get no
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better matches. */
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if (ar_right_targ != bfd_default_vector[0])
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ar_right_targ = *target;
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if (matching_vector)
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matching_vector[ar_match_index] = *target;
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ar_match_index++;
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}
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if (!bfd_preserve_save (abfd, &preserve))
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goto err_ret;
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}
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else if (bfd_get_error () != bfd_error_wrong_format)
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goto err_ret;
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}
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if (best_count == 1)
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match_count = 1;
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if (match_count == 0)
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{
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/* Try partial matches. */
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right_targ = ar_right_targ;
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if (right_targ == bfd_default_vector[0])
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{
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match_count = 1;
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}
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else
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{
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match_count = ar_match_index - _bfd_target_vector_entries;
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if (matching_vector && match_count > 1)
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memcpy (matching_vector,
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matching_vector + _bfd_target_vector_entries,
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sizeof (*matching_vector) * match_count);
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}
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}
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/* We have more than one equally good match. If any of the best
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matches is a target in config.bfd targ_defvec or targ_selvecs,
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choose it. */
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if (match_count > 1)
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{
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const bfd_target * const *assoc = bfd_associated_vector;
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while ((right_targ = *assoc++) != NULL)
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{
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int i = match_count;
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while (--i >= 0)
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if (matching_vector[i] == right_targ
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&& right_targ->match_priority <= best_match)
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break;
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if (i >= 0)
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{
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match_count = 1;
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break;
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}
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}
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}
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/* We still have more than one equally good match, and at least some
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of the targets support match priority. Choose the first of the
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best matches. */
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if (matching_vector && match_count > 1 && best_count != match_count)
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{
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int i;
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for (i = 0; i < match_count; i++)
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{
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right_targ = matching_vector[i];
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if (right_targ->match_priority <= best_match)
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break;
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}
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match_count = 1;
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}
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/* There is way too much undoing of half-known state here. We
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really shouldn't iterate on live bfd's. Note that saving the
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whole bfd and restoring it would be even worse; the first thing
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you notice is that the cached bfd file position gets out of sync. */
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if (preserve.marker != NULL)
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bfd_preserve_restore (abfd, &preserve);
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if (match_count == 1)
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{
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abfd->xvec = right_targ;
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/* If we come out of the loop knowing that the last target that
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matched is the one we want, then ABFD should still be in a usable
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state (except possibly for XVEC). */
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if (match_targ != right_targ)
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{
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bfd_reinit (abfd);
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if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
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goto err_ret;
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match_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
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BFD_ASSERT (match_targ != NULL);
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}
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ok_ret:
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/* If the file was opened for update, then `output_has_begun'
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some time ago when the file was created. Do not recompute
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sections sizes or alignments in _bfd_set_section_contents.
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We can not set this flag until after checking the format,
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because it will interfere with creation of BFD sections. */
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if (abfd->direction == both_direction)
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abfd->output_has_begun = TRUE;
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if (matching_vector)
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free (matching_vector);
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/* File position has moved, BTW. */
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return TRUE;
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}
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if (match_count == 0)
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{
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err_unrecog:
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bfd_set_error (bfd_error_file_not_recognized);
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err_ret:
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abfd->xvec = save_targ;
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abfd->format = bfd_unknown;
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if (matching_vector)
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free (matching_vector);
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if (preserve.marker != NULL)
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bfd_preserve_restore (abfd, &preserve);
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return FALSE;
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}
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/* Restore original target type and format. */
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abfd->xvec = save_targ;
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abfd->format = bfd_unknown;
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bfd_set_error (bfd_error_file_ambiguously_recognized);
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if (matching)
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{
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*matching = (char **) matching_vector;
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matching_vector[match_count] = NULL;
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/* Return target names. This is a little nasty. Maybe we
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should do another bfd_malloc? */
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while (--match_count >= 0)
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{
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const char *name = matching_vector[match_count]->name;
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*(const char **) &matching_vector[match_count] = name;
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}
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}
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return FALSE;
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}
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/*
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FUNCTION
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bfd_set_format
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SYNOPSIS
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bfd_boolean bfd_set_format (bfd *abfd, bfd_format format);
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|
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DESCRIPTION
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This function sets the file format of the BFD @var{abfd} to the
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format @var{format}. If the target set in the BFD does not
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support the format requested, the format is invalid, or the BFD
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is not open for writing, then an error occurs.
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*/
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bfd_boolean
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bfd_set_format (bfd *abfd, bfd_format format)
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{
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if (bfd_read_p (abfd)
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|| (unsigned int) abfd->format >= (unsigned int) bfd_type_end)
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{
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bfd_set_error (bfd_error_invalid_operation);
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return FALSE;
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}
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if (abfd->format != bfd_unknown)
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return abfd->format == format;
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/* Presume the answer is yes. */
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abfd->format = format;
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if (!BFD_SEND_FMT (abfd, _bfd_set_format, (abfd)))
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{
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abfd->format = bfd_unknown;
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return FALSE;
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}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/*
|
|
FUNCTION
|
|
bfd_format_string
|
|
|
|
SYNOPSIS
|
|
const char *bfd_format_string (bfd_format format);
|
|
|
|
DESCRIPTION
|
|
Return a pointer to a const string
|
|
<<invalid>>, <<object>>, <<archive>>, <<core>>, or <<unknown>>,
|
|
depending upon the value of @var{format}.
|
|
*/
|
|
|
|
const char *
|
|
bfd_format_string (bfd_format format)
|
|
{
|
|
if (((int) format < (int) bfd_unknown)
|
|
|| ((int) format >= (int) bfd_type_end))
|
|
return "invalid";
|
|
|
|
switch (format)
|
|
{
|
|
case bfd_object:
|
|
return "object"; /* Linker/assembler/compiler output. */
|
|
case bfd_archive:
|
|
return "archive"; /* Object archive file. */
|
|
case bfd_core:
|
|
return "core"; /* Core dump. */
|
|
default:
|
|
return "unknown";
|
|
}
|
|
}
|